In the retrail trade it is known to use a cash register for keying in the prices of the goods which a customer is purchasing and also for keying in the amount which a customer has paid. According to the prior art, a cash register comprises means for calculating the total cost of the goods, also called the requested amount, and means for calculating the difference between the amount tendered and the requested amount.
According to the prior art, the cash register is coupled to a receipt printer. The cash register has a function for supplying information to the receipt printer so that the latter is able to print out a receipt. It additionally has a command function which activates the receipt printer. The cash register furthermore comprises a data processing unit for calculating for example, the difference between the amount tendered and the requested amount, this unit functioning in compliance with software specially adapted for the cash register.
It is also known to couple to a cash register a device for processing the means of payment, this device being of the CashGuard type (registered trademark) which is described in EP-A-0 615 643 and whose purpose is to process, i.e. receive and assess, banknotes and coins in a reliable manner. The object of this device is moreover to supply the correct amount of change and in this way to eliminate or reduce the risk of financial loss and/or the possibility of taking money which is not due. However, if this device for processing payment is to be able to perform its tasks, it needs to share the information which the cash register processes. An example of information of this kinds is the requested amount.
According to the prior art, it is necessary to adapt the abovementioned software in the cash register in order to supply the correct information to the device processing the means of payment, and in order to ensure that the correct printouts are supplied from the cash register to the receipt printer.
The cash register and the device for processing the payment have been coupled together by connecting the latter directly to an interface in the cash register, which interface, depending on the manufacture and design of the cash register, it has been necessary to modify in order to obtain the desired function. This has been shown to be complicated and time consuming since it has to be done for each model and manufacture of cash register which is to be used together with a payment-processing device. One is forced to make changes to the cash register""s computer program, and this may require the assistance or the permission of the cash register manufacturer. In addition to this, today""s cash registers are often built into a computer network, and this may mean that it is not possible for modifications or connections to be made without the entire checkout system having to be closed down.
The problem to be solved by the invention compared to the nearest prior art is to enable joining up of a payment-processing device to a cash register and to a display arrangement without making it necessary to make modifications to the cash register.
One object of the present invention is to make available a system for the processing of means of payment including a payment-processing device which can be joined up, in an advantageously simple way, to a cash register and its receipt printer.
Another object of the present invention is to produce a payment-processing device which can be joined up to different types of cash registers without it being necessary to make modifications to the cash register, either in relation to its hardware or to its software.
A further object of this invention is to produce a device which, in a simple and cost-effective way, can upgrade existing cash registers, and can also, at limited expense, increase the reliability of processing of the means of payment.
These objects, and other ones which are evident from the following description, are achieved by a signal-processing device comprising a first data port for communication with a cash register, a second data port for communication with a display arrangement; and a third data port for communication with a payment-processing device. The signal-processing device also comprises means for receiving a first message at the first data port, control means for generating a second message as a function of the first messages and means for transmitting the second messages in a predetermined manner to the second data port as well as means for receiving a third message on the third data port, and means for generating an information quantity in response to the third message received on the third data port, the control means operating to deliver the generated information quantity to the second data port.
In an advantageous embodiment the system, according to the invention, for the processing of means of payment includes a signal processing device for cooperation with a computer program product such that control of the communication between the cash register, the payment-processing device and the display arrangement is effected. Such a computer program product comprises
a recording medium;
means, recorded on the recording medium, for directing the signal-processing device to receive a first message from a cash register,
means, recorded on the recording medium, for directing the signal-processing device, responsive to the received first message, to generate a second message; and
means, recorded on the recording medium, for directing the signal-processing device to transmit the second message in a predetermined manner to a display arrangement;
means, recorded on the recording medium, for directing the signal-processing device to await reception of a third message from a payment-processing device;
means, recorded on the recording medium, for directing the signal-processing device to generate an information quantity in response to the third message;
means, recorded on the recording medium, for directing the signal-processing device to deliver the generated information quantity to the display arrangement.
The claimed recording medium is illustrated in an example below by a memory element, and the claimed means, recorded on the recording medium, for directing the signal-processing device is illustrated in an example below by a program routine stored in the memory element.